ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) (Tables)

6 Months Ended

Jun. 30, 2022

Equity [Abstract]

Changes in Accumulated Other Comprehensive Income/(Loss) by Component, Net of Tax

The changes in accumulated other comprehensive income/(loss) by component, net of tax, are as follows:

	For the Six Months Ended June 30, 2022								For the Six Months Ended June 30, 2021
Eversource (Millions of Dollars)	Qualified Cash Flow Hedging Instruments		Unrealized Gains/(Losses) on Marketable Securities		Defined Benefit Plans		Total		Qualified Cash Flow Hedging Instruments		Unrealized Gains/(Losses) on Marketable Securities		Defined Benefit Plans		Total
Balance as of Beginning of Period	$	(0.4)	$	0.4	$	(42.3)	$	(42.3)	$	(1.4)	$	1.1	$	(76.1)	$	(76.4)
OCI Before Reclassifications	—		(1.3)		(2.5)		(3.8)		—		(0.5)		(2.4)		(2.9)
Amounts Reclassified from AOCI	—		—		3.2		3.2		0.9		—		4.1		5.0
Net OCI	—		(1.3)		0.7		(0.6)		0.9		(0.5)		1.7		2.1
Balance as of End of Period	$	(0.4)	$	(0.9)	$	(41.6)	$	(42.9)	$	(0.5)	$	0.6	$	(74.4)	$	(74.3)